From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/include/linux/virtio_ring.h | 67 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 kernel/include/linux/virtio_ring.h (limited to 'kernel/include/linux/virtio_ring.h') diff --git a/kernel/include/linux/virtio_ring.h b/kernel/include/linux/virtio_ring.h new file mode 100644 index 000000000..8e50888a6 --- /dev/null +++ b/kernel/include/linux/virtio_ring.h @@ -0,0 +1,67 @@ +#ifndef _LINUX_VIRTIO_RING_H +#define _LINUX_VIRTIO_RING_H + +#include +#include +#include + +/* + * Barriers in virtio are tricky. Non-SMP virtio guests can't assume + * they're not on an SMP host system, so they need to assume real + * barriers. Non-SMP virtio hosts could skip the barriers, but does + * anyone care? + * + * For virtio_pci on SMP, we don't need to order with respect to MMIO + * accesses through relaxed memory I/O windows, so smp_mb() et al are + * sufficient. + * + * For using virtio to talk to real devices (eg. other heterogeneous + * CPUs) we do need real barriers. In theory, we could be using both + * kinds of virtio, so it's a runtime decision, and the branch is + * actually quite cheap. + */ + +static inline void virtio_mb(bool weak_barriers) +{ +#ifdef CONFIG_SMP + if (weak_barriers) + smp_mb(); + else +#endif + mb(); +} + +static inline void virtio_rmb(bool weak_barriers) +{ + if (weak_barriers) + dma_rmb(); + else + rmb(); +} + +static inline void virtio_wmb(bool weak_barriers) +{ + if (weak_barriers) + dma_wmb(); + else + wmb(); +} + +struct virtio_device; +struct virtqueue; + +struct virtqueue *vring_new_virtqueue(unsigned int index, + unsigned int num, + unsigned int vring_align, + struct virtio_device *vdev, + bool weak_barriers, + void *pages, + bool (*notify)(struct virtqueue *vq), + void (*callback)(struct virtqueue *vq), + const char *name); +void vring_del_virtqueue(struct virtqueue *vq); +/* Filter out transport-specific feature bits. */ +void vring_transport_features(struct virtio_device *vdev); + +irqreturn_t vring_interrupt(int irq, void *_vq); +#endif /* _LINUX_VIRTIO_RING_H */ -- cgit 1.2.3-korg